Method and System for Detecting a Fallen Person Using a Range Imaging Device

1. A method for detecting a fallen person, comprising: generating an initial range image corresponding to a field of view of a data acquisition system; identifying a reference plane disposed in the field of view of the data acquisition system; determining one or more regions in the initial range image indicative of one or more objects disposed above the reference plane in the field of view of the data acquisition system; regenerating a range image corresponding to the field of view of the data acquisition system after a determined time period; comparing the regenerated range image with the initial range image to determine if the regenerated range image comprises a new object disposed above the reference plane; and determining whether the new object disposed above the reference plane is the fallen person if a height of the new object is less than a determined height and at least one of a volume and a surface area of the new object is greater than a determined value.

2. The method of claim 1 , wherein generating the range image corresponding to the field of view of the data acquisition system comprises generating a plurality of range values indicative of relative distances of one or more objects disposed in the field of view.

3. The method of claim 1 , wherein identifying the reference plane disposed in the field of view comprises identifying a group of pixels oriented as a plane disposed furthest from the data acquisition system or a plane disposed at a determined distance from the data acquisition system.

4. The method of claim 1 , wherein determining the one or more regions in the initial range image indicative of one or more objects disposed above the reference plane in the field of view of the data acquisition system comprises masking the one or more objects in the initial range image.

5. The method of claim 1 , wherein regenerating the range image corresponding to the field of view of the data acquisition system comprises continually regenerating the range image corresponding to the field of view of the data acquisition system after the determined time period.

6. The method of claim 1 , wherein comparing the regenerated range image with the initial range image further comprises determining a duration of a movement of the one or more objects, the new object, or a combination thereof, in the determined time period.

7. The method of claim 1 , wherein determining whether the new object disposed above the reference plane is the fallen person comprises designating a desired height as the determined height and at least one of a desired surface area and a desired volume as the determined value.

8. The method of claim 1 , further comprising generating an output upon determining that the fallen person is disposed above the reference plane for more than a determined duration of time.

9. The method of claim 8 , wherein generating the output comprises generating an audio output, a visual output, an alert message, or a combination thereof.

10. A system for detecting a fallen person, comprising: a data acquisition system that generates an initial range image corresponding to a field of view of the data acquisition system; and a processing subsystem, communicatively coupled to the data acquisition system, wherein the processing subsystem: identifies a reference plane disposed in the field of view of the data acquisition system; determines one or more regions in the initial range image indicative of one or more objects disposed above the reference plane in the field of view of the data acquisition system; regenerates a range image corresponding to the field of view of the data acquisition system after a determined time period; compares the regenerated range image with the initial range image to determine if the regenerated range image comprises a new object disposed above the reference plane; and determines whether the new object disposed above the reference plane is the fallen person if a height of the new object is less than a determined height and at least one of a volume and a surface area of the new object is greater than a determined value.

11. The system of claim 10 , wherein the data acquisition system comprises a range imaging device that uses the time-of-flight, coded aperture, structured light, or the triangulation principle.

12. The system of claim 10 , wherein the data acquisition system generates the initial range image corresponding to the field of view of the data acquisition system by generating a plurality of grey scale or color scale values indicative of a relative distance of the one or more objects disposed in the field of view.

13. The system of claim 10 , wherein the processing subsystem directs the data acquisition system to continually regenerate the range image corresponding to the field of view of the data acquisition system after the determined time period.

14. The system of claim 10 , wherein the processing subsystem further determines a duration of a movement of the one or more objects, the new object, or a combination thereof, in the determined time period.

15. The system of claim 14 , further comprising timing circuitry communicatively coupled to the processing subsystem through a wired network, a wireless network, or a combination thereof, for determining the determined time period corresponding to the regeneration of the range image and the determined duration of movement.

16. The system of claim 10 , further comprising an output unit that generates an output upon determining the fallen object is disposed on the floor for more than a determined duration of time, wherein the output unit is communicatively coupled to the processing subsystem through a wired network, a wireless network, or a combination thereof.

17. The system of claim 16 , wherein the output unit comprises an alarm unit, an audio transmitter, a video transmitter, a display unit, or combinations thereof.